A cross-wound push-pull downhole three-component fiber optic seismometer

The invention provides a cross-wound push-pull downhole three-component optical fiber seismometer, which belongs to the field of optical fiber interference measurement. It mainly includes a signal processing system, a signal acquisition system, a vector accelerometer, a communication cable and an optical cable. Two sensing units with the same structure are orthogonally stacked to form a three-dimensional vector sensing probe. The outside is protected by an outer cylinder and a sealed end cap. The sensitive optical fiber adopts the form of external winding, and the main structural components are enclosed inside the sensitive optical fiber. At the same time, the sensitive optical fiber is cross-wound between the two leaf spring fixing blocks and the two fiber winding columns, and together with the mass block forms a push-pull structure, wherein the mass block directly stretches the sensitive fiber through the fiber winding columns at both ends. The advantages of the device are that the vibration direction of the mass block is good, the lateral crosstalk is low, high strain transfer efficiency and sensitivity can be achieved, and the structure is compact, which can meet the measurement requirements in narrow spaces, and is especially suitable for deep well seismic observation.